Videoroom A/V Sync Issues

[kylefoley]

We're seeing audio/video not synced - note the googCurrentDelayMS in the graph which seems to be growing. In this case, the audio was ahead of the video by 1s. The audio googCurrentDelayMS was about 50ms.

I can attach a WebRTC dump if necessary. Any help in debugging it would be appreciated appreciated. Thanks!

Janus v0.7.1 Video Codec - H264 Audio Codec - OPUS Browsers - Chrome v74 Using CoTURN MacOS on one side, Win10 on the other

[lminiero]

Please test the PR above.

[ghost]

We see the lipsync issue as well.

Using the latest master version of Janus, videoroom plugin, Chrome 80 (Windows) on both ends, Alice and Bob. Bob's video gets about 1 sec out of sync with his audio (video is 1 sec delayed. as viewed by Alice). Alice's video and audio (as viewed by Bob) stay in sync.

Sync problem does not occur every time--it seems to start after there's been some kind of 'hiccup' in the connection that causes a momentary packet loss and/or packet nacks. But thereafter, the sync problem persists in that PeerConnection. If we destroy that PeerConnection and then create a new PC, the sync problem goes away... at least until it comes back again after another connection 'hiccup'.

I'll try to record pcap once I figure out how to do that.

[lminiero]

Please only provide feedback and pcaps if they refer to the PR above. We're not interested in data from master: we already know the issue may arise. We need information on whether the PR we came up with helps or not.

[ghost]

Understood. I'll try the PR rather than the master.

[ghost]

The PR (#2007) does appear to fix the sync issue. Will continue testing, but looks good.

[lminiero]

Merged, so I'll close.